guestfs-ruby man page

This manual page documents how to call libguestfs from the Ruby programming language. This page just documents the differences from the C API and gives some examples. If you are not familiar with using libguestfs, you also need to read guestfs(3).

# Example showing how to create a disk image.
require 'guestfs'
output = "disk.img"
g = Guestfs::Guestfs.new()
# Create a raw-format sparse disk image, 512 MB in size.
g.disk_create (output, "raw", 512 * 1024 * 1024)
# Set the trace flag so that we can see each libguestfs call.
g.set_trace(1)
# Attach the disk image to libguestfs.
g.add_drive_opts(output, :format => "raw")
# Run the libguestfs back-end.
g.launch();
# Get the list of devices. Because we only added one drive
# above, we expect that this list should contain a single
# element.
devices = g.list_devices()
if devices.length != 1 then
raise "error: expected a single device from list-devices"
end
# Partition the disk as one single MBR partition.
g.part_disk(devices[0], "mbr")
# Get the list of partitions. We expect a single element, which
# is the partition we have just created.
partitions = g.list_partitions()
if partitions.length != 1 then
raise "error: expected a single partition from list-partitions"
end
# Create a filesystem on the partition.
g.mkfs("ext4", partitions[0])
# Now mount the filesystem so that we can add files.
g.mount(partitions[0], "/")
# Create some files and directories.
g.touch("/empty")
message = "Hello, world\n"
g.write("/hello", message)
g.mkdir("/foo")
# This one uploads the local file /etc/resolv.conf into
# the disk image.
g.upload("/etc/resolv.conf", "/foo/resolv.conf")
# Because we wrote to the disk and we want to detect write
# errors, call g.shutdown. You don't need to do this:
# g.close will do it implicitly.
g.shutdown()
# Note also that handles are automatically closed if they are
# reaped by the garbage collector. You only need to call close
# if you want to close the handle right away.
g.close()